I’ve always won­dered why some water sup­plies have trace amounts of flu­o­ride in them. I dream some­times that it’s a gov­ern­ment con­spir­acy in the best kind of way: they are dos­ing us to become the world’s strongest, high­est jump­ing peo­ple with the best sense of rhythm. When­ever I eat me some flu­o­ride, I am becom­ing so much awe­somer you don’t even know.

But I think it might be instead because research has (almost cer­tainly) shown that some people’s teeth can be so huge that peo­ple are too lazy to brush them with enough flu­o­ride tooth­paste. Lead­ing tech­ni­cians will tell you that if you dyed the tooth­paste red the only part of the tooth that you will find ade­quately brushed will be your left upper bicus­pids. We don’t know what hap­pens to all the other teeth. We sus­pect that your hands, which are respon­si­ble for the tooth­brush, hate you.